Keto Flu: Symptoms, Timeline, And How Long It Lasts

Keto Flu: Symptoms, Timeline, And How Long It Lasts

Starting a ketogenic diet tends to be a bit tough. Not only do you need to adjust to eating fewer carbohydrates than usual, but you also run the risk of "contracting" the keto flu. Sure, the weight loss and health benefits of the keto diet are worth powering through those first few weeks. However, you also need to be prepared for what's to come as your body adjusts to the difference in macros.

Yes, the keto flu is a real thing. Although not everyone ends up with it, the keto flu can make you feel under the weather for a bit. What else do you need to know about the keto flu? Keep reading to find out.

Beginning a Keto Diet 

The keto diet is designed to send the body into ketosis. This means that it will begin to burn off fat stores called ketones for energy, causing you to lose weight. However, in order to get to that point, you need to eat a specific ratio of macros, including fewer carbohydrates than usual.

The other macros—protein and healthy fats—are raised to make up for the lower number of carbs. In addition to cutting the carbs (this means pasta, bread, and premade treats, like cupcakes and brownies), you also need to cut back on sugar. The two are related, after all, and eating too many of them will not only help you gain the belly fat that you want to lose, but it will also prevent you from going into ketosis.

Basically, for the keto diet to do what it's supposed to, you need to watch what you eat, carefully plan your meals, and spend time doing meal prep to ensure that you stay within your macros.

However, there's one additional thing that you may have to prepare yourself for: the keto flu.

What Is the Keto Flu? 

Despite its name, the keto flu isn't the actual flu. The standard flu that you're used to contracting is caused by a virus, and it can cause everything from stomach upset to nasal congestion, coughing, and general aches and pains. The keto flu isn't caused by a virus, although some symptoms are the same.

The keto flu causes side effects like fatigue, headaches, nausea, dizziness, and irritability. You might also feel a bit of brain fog, leaving you unable to concentrate as well as you previously could. Trouble sleeping and constipation are two other possible symptoms of keto flu.

Some of the symptoms of the standard flu, such as nasal congestion, aren't present in the keto flu. While the aches and pains may be similar, there's a marked difference between the two.

Why do you get the keto flu after starting the diet? Since you've no doubt eaten a lot of carbs in the past (and who hasn't?), your body needs to transition to a diet that includes much less of them. This can throw your system out of whack, causing your blood sugar to lower, among other things.

When this happens, you begin to feel bad, but there's one good thing to focus on amongst it all – feeling as though you have the keto flu means that your body is entering into a state of ketosis.

When Do You Get The Keto Flu? 

Usually, keto flu symptoms pop up a few days after you've started the diet. Around three to four days seems to be the norm. However, it can take up to a week to appear. This depends on a number of things, such as how many carbs you routinely ate before starting the diet, as well as how strictly you cut back on them once you began counting those macros.

For example, if you regularly ate upwards of 500 grams of carbohydrates per day (this is above the recommended number of 200 to 300 per day), and cut down to less than 50 very quickly, then you'll end up shocking your body and causing the keto flu to appear.

It could happen quickly after starting the diet. With that said, people who ate fewer carbs to begin with might not shock their systems as much once they start the keto diet, causing the keto flu to take a little longer to pop up.

While many people get the keto flu shortly after starting the diet, not all of them do. Some people go into ketosis without getting the keto flu at all. It all depends on how their bodies handle the beginning phases of the diet.

Treating the Keto Flu 

Thankfully, the keto flu tends to only last for a few days. Once your body adjusts to your new diet, the symptoms will fade. In the meantime, there are a few keto flu remedies that you can try to minimize the symptoms and get yourself back to a functional state.

Drink Plenty Of Water 

As with the regular flu, it's important to stay as hydrated as possible when suffering from the keto flu. Water will help flush your system and prevent you from dehydration should you end up with vomiting or diarrhea.

It's also a good idea to drink a lot of water while on the keto diet in the first place, since the glycogen stores in your body (caused by excess carbs) tend to bind with the water in your system. When those glycogen stores are flushed through your digestive system, they take the water along with it, making you more likely to get dehydrated. Dehydration can also contribute to the muscle cramps, muscle soreness, and muscle weakness that comes alongside the keto flu.

Go Easy on Yourself

You just started a new diet and are feeling the effects of it. Now is not the time to push yourself to run a marathon or clean your entire house from top to bottom. If you're feeling bad, sit back and rest. The more that you relax and take it easy, the quicker you'll begin to feel better.

Just as you would with the regular flu, you need to spend some time napping, watching television, and reading books to keep your mind off of your symptoms.

Eat a Few Carbs 

While you don't want to throw your body out of ketosis, which means that you'll need to start all over again, having one carb-filled snack that keeps you under the 50-gram limit might make you feel a little better. After all, your body is adjusting to not having the usual amount of carbs in its system and may experience carb withdrawal.

By eating a small number of carbs, you'll minimize those symptoms and give your digestive system what it craves. Plus, colorful non-starchy vegetables should still make an appearance on this low-carb diet, especially if you're feeling run down. Just make sure to keep an eye on your macros in order to stay within your usual carb intake range.

Get Some Sleep 

Not only do you need to take it easy in order to get through the keto flu, but you also need to get plenty of sleep. You might have a bit of insomnia as a result of the lower amount of carbs in your system and the adjustments that your body is going through, but the best thing for you right now is sleep.

Once you manage to conk out, you won't notice that your body is mad at you, temporarily at least.

Don't Forget the Electrolytes

One of the best things for you when you have the keto flu is electrolytes. Found in beverages like Gatorade and Powerade (both of which have plenty of sugar, so look for sugar-free versions), as well as SmartWater, these electrolytes will replace the ones your body has lost due to your dietary change.

If you don't want to drink your electrolytes, look for foods that contain plenty of potassium (avocados and beans), magnesium (kale), and other micros that you'll need in order to feel better.

Avoiding the Keto Flu Like a Pro

While some people manage to avoid the keto flu because their bodies adjust better to the diet, others still suffer from it. Although the keto flu is a sign that the diet is working, it can be miserable to go through.

Thankfully, you can try to avoid it by cutting back the number of carbs that you eat very slowly. This is a particularly good idea if you're used to eating more than 500 grams of carbs per day. By cutting back a little at a time, you'll take longer to go into ketosis, but your body will be less shocked when it reaches that state.


Why Does The Keto Diet Cause Flu-Like Symptoms? | Medical News Today

The Keto Flu: Symptoms And How To Get Rid Of It | Healthline

What Is Keto Flu? | Harvard Health Blog